1. Field of the Invention
The present invention relates to a tape player into which a cassette accommodating a tape is loaded. More particularly, the present invention pertains to a cassette loading apparatus designed to guide a cassette onto a chassis and to eject the cassette from the chassis when it is to be unloaded.
2. Description of the Related Art
Prior to the description of the present invention, a conventional cassette loading apparatus for a tape player will be explained below with reference to FIGS. 8 to 11. This prior art is disclosed, e.g., in the specification of Japanese Utility Model Laid-Open No. 3539/1986.
In the drawings, the reference numeral 1 denotes cassette holders. As shown in FIG. 11, a pair of cassette holders 1 are respectively provided on the opposing inner surfaces of side plates 2a of a chassis 2. Guide grooves 1a for retaining the lateral edge portions of a cassette 10 are respectively formed in the opposing inner side surfaces of the cassette holders 1. As shown in FIG. 8, a guide pin 3 and a connecting pin 4 are provided on the outer side surface of each cassette holder 1. The pins 3 and 4 are vertically movably guided by slots which are formed in each of the side plates 2a of the chassis 2 in such a manner that the slots extend vertically. When no cassette 10 is loaded, the cassette holders 1 are in a raised position as shown in FIG. 8.
Referring to FIG. 10, a pair of ejector links 5 and 6 are provided on the chassis 2. One ejector link 5 is pivotally supported by a pin 7, and the other ejector link 6 is pivotally supported by a pin 8. The ejector links 5 and 6 are operatively connected together by a connecting pin 9. The ejector link 5 is biased counterclockwise as viewed in FIG. 10 by means of a spring 11. When no cassette half 10 is loaded, the ejector link 5 is pivoted counterclockwise, while the ejector link 6 is pivoted clockwise, and pressing portions 5a and 6a provided at the respective distal ends of the ejector links 5 and 6 extend above the chassis 2 as shown by the one-dot chain line in FIG. 10.
When the cassette 10 is loaded, it is pushed into the cassette accommodating space defined by the chassis 2 in such a manner that both lateral edge portions of the cassette 10 are respectively guided by the guide grooves 1a of the cassette holders 1 which are in the raised position shown in FIG. 8. The ejector links 5 and 6, which are in the position shown by the one-dot chain line in FIG. 10, are pushed by the distal end surface of the cassette 10 and contracted to the position shown by the solid line in FIG. 10. In response to the contracting movement of the ejector links 5 and 6, a driving piece 6b provided at the distal end of the ejector link 6 moves from the position (A) to the position (B) shown in FIG. 10. Since the driving piece 6b is connected to a lock lever 12 provided on the outer side of the side plate 2a of the chassis 2 as shown in FIG. 8, when the driving piece 6b moves from the position (A) to the position (B), the lock lever 12 moves rightward from the position shown in FIG. 8 together with the driving piece 6b to reach the position shown in FIG. 9. A driving link 14 is pivotally supported through a pivot pin 13 on the outer side of the side plate 2a of the chassis 2, so that, when the lock lever 12 moves rightward from the position shown in FIG. 8, a retaining portion 12a provided at the lower end of the lock lever 12 disengages from the distal end of a projecting piece 14a of the driving link 14. In consequence, tha driving link 14 is pivoted clockwise by means of the biasing force from a spring 15 to reach the position shown in FIG. 9. A slot 14b provided in the distal end portion of the driving link 14 is retained by the connecting pin 4, so that, when the driving link 14 is pivoted clockwise, the cassette holders 1 are lowered onto the chassis 2 through the connecting pin 4 as shown in FIG. 9, and the cassette 10 is thereby loaded in a state wherein it is in contact with positioning pins 16 projecting from the surface of the chassis 2 (see FIG. 11).
To eject the cassette 10, an unlocking lever 17 is moved rightward as viewed in FIG. 9. An unlocking piece 17a of the unlocking lever 17 causes the driving link 14 to pivot counterclockwise from the position shown in FIG. 9. In consequence, the cassette holders 1 are raised, and the cassette 10 is thereby lifted from the surface of the chassis 2. Since the lock lever 12 is biased in the direction of the arrow A together with the driving piece 6b of the ejector lever 6 by means of the biasing force from the spring 11, when the driving link 14 is pivoted counterclockwise by the action of the unlocking lever 17, the projecting piece 14a is locked by the retaining portion 12a of the lock lever 12 again as shown in FIG. 8. Each of the ejector levers 5 and 6 extends to reach the position shown by the one-dot chain line in FIG. 10, and the cassette 10 is pushed out from the cassette accommodating space by the pressing portions 5a and 6a.
This type of conventional tape loading apparatus suffers, however, from the following problems.
The conventional tape loading apparatus has a pair of driving links 14 which are respectively provided on the outer sides of the side plates 2a of the chassis 2 and which are connected to each other by a connecting member 18. Accordingly, the pair of driving links 14 are activated together in one unit, and the cassette holders 1 which are provided at the right and left sides, respectively, on the chassis 2, are also activated to move together in one unit.
In order that the cassette 10 is appropriately or normally loaded on the positioning pins 16 projecting from the surface of the chassis 2, both lateral edge portions of the cassette 10 must reliably and effectively be held down by the pair of cassette holders 1. However, in the conventional structure, since the right and left driving links 14 are connected together in one unit, it is necessary to adjust the relative positions of the driving links 14 in order to enable the lateral edge portions of the cassette half 10 to be reliably and effectively held down by the two cassette holders 1. For this reason, the connecting member 18 and one driving link 14 are connected together by means of a screw 19, and the relative positions of the right and left driving links 14 are adjusted by adjusting the position of the screw 19 so that the two driving links 14 evenly lower the right and left cassette holders 1.
If tee adjustment by the screw 19 is erroneously effected so that the respective lowered positions of the two cassette holders 1 are not coincident with each other, the respective lowered positions of the lateral edge portions of the cassette 10 ar vertically offset from each other, which means that the cassette 10 is not normally loaded on the positioning pins 16.
Thus, the conventional structure needs the adjustment of the positions of the right and left driving links 14, and this considerably complicates the assembling operation, disadvantageously.
Even when the positions of the right and left driving links 14 are set optically by the adjusting operation, if cassette 10 has warpage or variations in flatness, it is impossible to reliably lower the cassette 10 onto the chassis 2 by means of the right and left cassette holders 1 which are lowered uniformly in one unit. In such case also, an undesirable gap is generated between the cassette 10 and the positioning pins 16, thus making it impossible to load the cassette 10 in a normal state.